This application claims priority of Korea patent Application No. 99-66647, filed on Dec. 30, 1999.
(a) Field of the Invention
The present invention relates to an automotive engine control method and, more particularly, to an engine control method for an automatic transmission vehicle equipped with an electric throttle control (ETC) device for reducing shift shocks, in which engine torque of each speed range relative to the acceleration pedal displacement is calculated and the throttle is adjusted such that the engine torque is guided by a formulated line.
(b) Description of the Related Art
Typically, an automatic transmission vehicle equipped with an ETC device performs a speed range shift control by a shift pattern predetermined in accordance with vehicle speed and throttle opening.
In this case, to reduce shift impact generated during a speed range shift, shift control means sends a combined control signal to an engine control means so as to degrade engine torque.
However, this engine control mechanism has drawbacks in that value of engine torque is calculated at every shift range for compensating a torque displacement during the shift operation, and the engine torque reduction according to the combination control deteriorates engine performance and fuel consumption.
The present invention has been made in an effort to solve the above problems of the prior art.
It is an object of the present invention to provide an engine control method for an automatic transmission vehicle equipped with an electric throttle control (ETC) device for reducing shift shocks, in which engine torque of each speed range relative to the acceleration pedal displacement is calculated and the throttle opening is adjusted such that the engine torque is guided along the formulated line during speed range shift.
To achieve the above object, the engine control method for an automotive vehicle of the present invention comprises the steps of gathering and analyzing vehicle condition parameters from a vehicle condition detecting means, determining whether a signal from a TCU is a shift signal or not, converting a throttle opening versus vehicle speed shift line into an engine torque versus vehicle speed shift line, and if the signal from the TCU is a shift signal, determining if a present acceleration pedal displacement value relative to the engine torque is less than a predetermined value, and synchronizing the engine torque to a predetermined value if the acceleration pedal displacement value indicates the engine torque is less than the predetermined value.